If you like the classic Fallout games such as the first two, you'll like Wasteland 2 - which is faithful to the CRPG format that went missing for some years and even expands upon it.
If you like old-school shooters such as Duke Nukem and Shadow Warrior, you'll like Shadow Warrior (2013), developed by Flying Wild Hog, the developers of Hard Reset. It's a wonderful return to form that is frequently on sale on Steam and has had console ports to PS4 and Xbox One recently. I don't recommend it at $60, which is good because it was never $60.
If you like XCOM: Enemy Unknown and stealth games, you'll like Invisible, Inc. It was developed by Klei, creators of Don't Starve, Mark of the Ninja, Shank, and Eets. Rather than direct combat, you'll frequently be required to remain in stealth and consider your tactics, positioning, and manage your resources carefully.
If you like Civilization, you'll like Endless Legend. I haven't played many 4X games in my life, so I'm sure games like Fallen Enchantress might resemble Endless Legend better, with its use of heroes and a dedicated combat system. Regardless, Endless Legend is oozing with the kind of depth that a strategy gamer would love to pick up and play.
If you like platformers such as the Genesis-era Sonic the Hedgehog games, you'll like Freedom Planet, an indie game that is as much a love letter to Sonic as it is to platformers in general. It's not a Sonic clone by any means, but a very fun side-scrolling action-platforming game that provides plenty of meaty challenge to keep you invested, along with multiple playable characters, and a beautiful 16-bit art style that apes the Genesis just as well as Shovel Knight apes the NES. In fact, both were released in 2014, and Freedom Planet very much feels like the Genesis platformer to the NES platformer that is Shovel Knight. The spirit of Sega and Nintendo console wars lives on in them both. And ironically, it's on the Wii U now... like Sonic...
I tried to avoid games I think a lot of people will really know the names of. I mentioned Wasteland 2 because it's known more for its Kickstarter success. Endless Legend got acknowledged as one of his top ten games of 2014, but outside of that, I don't see much mention of it. And it has a $10 expansion pack now. Don't bother with the dev's previous 4X game, Endless Space, unless you really want a space 4X. I don't think it has staying power Legend does.